Business Combinations (Details Textual) (USD $)	3 Months Ended	12 Months Ended						3 Months Ended		6 Months Ended		6 Months Ended		9 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended	3 Months Ended		12 Months Ended
	Jun. 30, 2010 Branch	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 First Bank Branches [Member]	Dec. 31, 2010 First Bank Branches [Member]	Feb. 19, 2010 First Bank Branches [Member] Branch	Mar. 31, 2011 Midwest Bank and Trust Company [Member]	Sep. 30, 2010 Midwest Bank and Trust Company [Member] Branch	Jun. 30, 2011 Midwest Bank and Trust Company [Member]	May 14, 2010 Midwest Bank and Trust Company [Member]	Jun. 30, 2011 Midwest Bank and Trust Company [Member] Other Loan [Member]	Jun. 30, 2011 George Washington Savings Bank [Member]	Sep. 30, 2010 George Washington Savings Bank [Member]	Dec. 31, 2011 George Washington Savings Bank [Member]	Jun. 30, 2010 George Washington Savings Bank [Member]	Feb. 19, 2010 George Washington Savings Bank [Member]	Jun. 30, 2011 George Washington Savings Bank [Member] Commercial [Member]	Dec. 31, 2011 George Washington Savings Bank [Member] Single Family Residential Mortgage Loan [Member]	Mar. 31, 2010 George Washington [Member]	Dec. 31, 2011 George Washington [Member]	Dec. 31, 2011 Abl Loan Acquisition [Member]	Dec. 16, 2009 Abl Loan Acquisition [Member]
Business Acquisition [Line Items]
Business Combination Recognized Identifiable Assets Acquired																							$ 102,000,000
Increase Decrease in Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Asset Based Loans Fair Value																							92,700,000
Finite-Lived Intangible Assets, Gross		17,479,000	17,479,000																				100,000
Goodwill, Acquired During Period						48,347,000																400,000
Cash received to assume net liabilities		0	969,767,000	0	832,500,000										40,200,000
Number of former George Washington branches purchased	3
Cash payment made by bank to FDIC											227,500,000												93,200,000
Number of Branches Purchased using options									10
Reimbursement Period under Loss Sharing Agreements												10 years						10 years
Loss Sharing Agreement Period for commercial loans																		5 years
Loss Sharing Agreement Period for other than single family residential mortgage loans												5 years
Bank reimbursement period to FDIC												8 years						8 years
Estimated fair value of covered loans											1,800,000,000						177,800,000
Expected reimbursement for losses on the Covered Loans											260,700,000		88,700,000
Estimated fair value of the covered other real estate											26,200,000						11,500,000
Expected reimbursement for losses to be incurred by the Bank on covered other real estate										2,200,000			11,300,000
Decrease in estimated fair value of the Covered Loans								39,400,000						(6,300,000)
Increase (Decrease) in FDIC loss share receivable on the Covered Loans								(23,900,000)						7,500,000
Increase in other liabilities								2,300,000						(5,200,000)
FDIC Loss Increase In Accrued Interest								5,400,000
FDIC loss share receivable Increase in other assets								20,600,000
Goodwill		460,044,000	460,044,000	139,598,000				272,100,000
Bargain purchase gain													1,000,000							1,000,000
Percent of asset discount under loss sharing agreements													25.00%
Asset discount received													47,000,000
Bargain purchase, net of tax													700,000
Percent of cumulative shared loss payments under loss sharing agreements										25.00%			25.00%
Percent of excess threshold paid by the Bank under loss sharing agreements													50.00%
Estimated True Up Liability																	5,200,000
Decrease in bargain purchase gain															4,000,000
Reduction in true-up liability										6,300,000
Period after closing date fair value estimates subject to change													Up to one year
Number of branches							24
Combined Purchase Price									25,100,000							4,300,000
Goodwill impairment loss								5,600,000
Percent of losses under loss sharing agreements below threshold reimbursable by FDIC										80.00%			80.00%
Percent of losses under loss sharing agreements above threshold reimbursable by FDIC													95.00%
Threshold for losses under loss sharing agreements reimbursable by FDIC													172,000,000
Percent of recoveries under loss sharing agreements below threshold reimbursable by the Bank										80.00%			80.00%
Percent of recoveries under loss sharing agreements above threshold reimbursable by Bank													95.00%
Percent of losses under loss sharing agreements below threshold reimbursable by FDIC													80.00%
Percent of recoveries under loss sharing agreements above threshold paid by FDIC													95.00%
Percent of FDIC intrinsic loss estimate										20.00%			20.00%
FDIC intrinsic loss estimate										152,000,000
Percent of Asset premium paid									25.00%
Asset premium paid										20,000,000
Reimbursement Period to FDIC																			10 years
Estimated fair value of true up liability															$ 7,200,000						$ 4,300,000